linux/fs/ioctl.c
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   1/*
   2 *  linux/fs/ioctl.c
   3 *
   4 *  Copyright (C) 1991, 1992  Linus Torvalds
   5 */
   6
   7#include <linux/syscalls.h>
   8#include <linux/mm.h>
   9#include <linux/capability.h>
  10#include <linux/file.h>
  11#include <linux/fs.h>
  12#include <linux/security.h>
  13#include <linux/export.h>
  14#include <linux/uaccess.h>
  15#include <linux/writeback.h>
  16#include <linux/buffer_head.h>
  17#include <linux/falloc.h>
  18#include "internal.h"
  19
  20#include <asm/ioctls.h>
  21
  22/* So that the fiemap access checks can't overflow on 32 bit machines. */
  23#define FIEMAP_MAX_EXTENTS      (UINT_MAX / sizeof(struct fiemap_extent))
  24
  25/**
  26 * vfs_ioctl - call filesystem specific ioctl methods
  27 * @filp:       open file to invoke ioctl method on
  28 * @cmd:        ioctl command to execute
  29 * @arg:        command-specific argument for ioctl
  30 *
  31 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
  32 * returns -ENOTTY.
  33 *
  34 * Returns 0 on success, -errno on error.
  35 */
  36long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  37{
  38        int error = -ENOTTY;
  39
  40        if (!filp->f_op->unlocked_ioctl)
  41                goto out;
  42
  43        error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
  44        if (error == -ENOIOCTLCMD)
  45                error = -ENOTTY;
  46 out:
  47        return error;
  48}
  49
  50static int ioctl_fibmap(struct file *filp, int __user *p)
  51{
  52        struct address_space *mapping = filp->f_mapping;
  53        int res, block;
  54
  55        /* do we support this mess? */
  56        if (!mapping->a_ops->bmap)
  57                return -EINVAL;
  58        if (!capable(CAP_SYS_RAWIO))
  59                return -EPERM;
  60        res = get_user(block, p);
  61        if (res)
  62                return res;
  63        res = mapping->a_ops->bmap(mapping, block);
  64        return put_user(res, p);
  65}
  66
  67/**
  68 * fiemap_fill_next_extent - Fiemap helper function
  69 * @fieinfo:    Fiemap context passed into ->fiemap
  70 * @logical:    Extent logical start offset, in bytes
  71 * @phys:       Extent physical start offset, in bytes
  72 * @len:        Extent length, in bytes
  73 * @flags:      FIEMAP_EXTENT flags that describe this extent
  74 *
  75 * Called from file system ->fiemap callback. Will populate extent
  76 * info as passed in via arguments and copy to user memory. On
  77 * success, extent count on fieinfo is incremented.
  78 *
  79 * Returns 0 on success, -errno on error, 1 if this was the last
  80 * extent that will fit in user array.
  81 */
  82#define SET_UNKNOWN_FLAGS       (FIEMAP_EXTENT_DELALLOC)
  83#define SET_NO_UNMOUNTED_IO_FLAGS       (FIEMAP_EXTENT_DATA_ENCRYPTED)
  84#define SET_NOT_ALIGNED_FLAGS   (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
  85int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
  86                            u64 phys, u64 len, u32 flags)
  87{
  88        struct fiemap_extent extent;
  89        struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
  90
  91        /* only count the extents */
  92        if (fieinfo->fi_extents_max == 0) {
  93                fieinfo->fi_extents_mapped++;
  94                return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
  95        }
  96
  97        if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
  98                return 1;
  99
 100        if (flags & SET_UNKNOWN_FLAGS)
 101                flags |= FIEMAP_EXTENT_UNKNOWN;
 102        if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
 103                flags |= FIEMAP_EXTENT_ENCODED;
 104        if (flags & SET_NOT_ALIGNED_FLAGS)
 105                flags |= FIEMAP_EXTENT_NOT_ALIGNED;
 106
 107        memset(&extent, 0, sizeof(extent));
 108        extent.fe_logical = logical;
 109        extent.fe_physical = phys;
 110        extent.fe_length = len;
 111        extent.fe_flags = flags;
 112
 113        dest += fieinfo->fi_extents_mapped;
 114        if (copy_to_user(dest, &extent, sizeof(extent)))
 115                return -EFAULT;
 116
 117        fieinfo->fi_extents_mapped++;
 118        if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
 119                return 1;
 120        return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 121}
 122EXPORT_SYMBOL(fiemap_fill_next_extent);
 123
 124/**
 125 * fiemap_check_flags - check validity of requested flags for fiemap
 126 * @fieinfo:    Fiemap context passed into ->fiemap
 127 * @fs_flags:   Set of fiemap flags that the file system understands
 128 *
 129 * Called from file system ->fiemap callback. This will compute the
 130 * intersection of valid fiemap flags and those that the fs supports. That
 131 * value is then compared against the user supplied flags. In case of bad user
 132 * flags, the invalid values will be written into the fieinfo structure, and
 133 * -EBADR is returned, which tells ioctl_fiemap() to return those values to
 134 * userspace. For this reason, a return code of -EBADR should be preserved.
 135 *
 136 * Returns 0 on success, -EBADR on bad flags.
 137 */
 138int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
 139{
 140        u32 incompat_flags;
 141
 142        incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
 143        if (incompat_flags) {
 144                fieinfo->fi_flags = incompat_flags;
 145                return -EBADR;
 146        }
 147        return 0;
 148}
 149EXPORT_SYMBOL(fiemap_check_flags);
 150
 151static int fiemap_check_ranges(struct super_block *sb,
 152                               u64 start, u64 len, u64 *new_len)
 153{
 154        u64 maxbytes = (u64) sb->s_maxbytes;
 155
 156        *new_len = len;
 157
 158        if (len == 0)
 159                return -EINVAL;
 160
 161        if (start > maxbytes)
 162                return -EFBIG;
 163
 164        /*
 165         * Shrink request scope to what the fs can actually handle.
 166         */
 167        if (len > maxbytes || (maxbytes - len) < start)
 168                *new_len = maxbytes - start;
 169
 170        return 0;
 171}
 172
 173static int ioctl_fiemap(struct file *filp, unsigned long arg)
 174{
 175        struct fiemap fiemap;
 176        struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
 177        struct fiemap_extent_info fieinfo = { 0, };
 178        struct inode *inode = file_inode(filp);
 179        struct super_block *sb = inode->i_sb;
 180        u64 len;
 181        int error;
 182
 183        if (!inode->i_op->fiemap)
 184                return -EOPNOTSUPP;
 185
 186        if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
 187                return -EFAULT;
 188
 189        if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
 190                return -EINVAL;
 191
 192        error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
 193                                    &len);
 194        if (error)
 195                return error;
 196
 197        fieinfo.fi_flags = fiemap.fm_flags;
 198        fieinfo.fi_extents_max = fiemap.fm_extent_count;
 199        fieinfo.fi_extents_start = ufiemap->fm_extents;
 200
 201        if (fiemap.fm_extent_count != 0 &&
 202            !access_ok(VERIFY_WRITE, fieinfo.fi_extents_start,
 203                       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
 204                return -EFAULT;
 205
 206        if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
 207                filemap_write_and_wait(inode->i_mapping);
 208
 209        error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
 210        fiemap.fm_flags = fieinfo.fi_flags;
 211        fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 212        if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
 213                error = -EFAULT;
 214
 215        return error;
 216}
 217
 218static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
 219                             u64 off, u64 olen, u64 destoff)
 220{
 221        struct fd src_file = fdget(srcfd);
 222        int ret;
 223
 224        if (!src_file.file)
 225                return -EBADF;
 226        ret = vfs_clone_file_range(src_file.file, off, dst_file, destoff, olen);
 227        fdput(src_file);
 228        return ret;
 229}
 230
 231static long ioctl_file_clone_range(struct file *file, void __user *argp)
 232{
 233        struct file_clone_range args;
 234
 235        if (copy_from_user(&args, argp, sizeof(args)))
 236                return -EFAULT;
 237        return ioctl_file_clone(file, args.src_fd, args.src_offset,
 238                                args.src_length, args.dest_offset);
 239}
 240
 241#ifdef CONFIG_BLOCK
 242
 243static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 244{
 245        return (offset >> inode->i_blkbits);
 246}
 247
 248static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 249{
 250        return (blk << inode->i_blkbits);
 251}
 252
 253/**
 254 * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
 255 * @inode: the inode to map
 256 * @fieinfo: the fiemap info struct that will be passed back to userspace
 257 * @start: where to start mapping in the inode
 258 * @len: how much space to map
 259 * @get_block: the fs's get_block function
 260 *
 261 * This does FIEMAP for block based inodes.  Basically it will just loop
 262 * through get_block until we hit the number of extents we want to map, or we
 263 * go past the end of the file and hit a hole.
 264 *
 265 * If it is possible to have data blocks beyond a hole past @inode->i_size, then
 266 * please do not use this function, it will stop at the first unmapped block
 267 * beyond i_size.
 268 *
 269 * If you use this function directly, you need to do your own locking. Use
 270 * generic_block_fiemap if you want the locking done for you.
 271 */
 272
 273int __generic_block_fiemap(struct inode *inode,
 274                           struct fiemap_extent_info *fieinfo, loff_t start,
 275                           loff_t len, get_block_t *get_block)
 276{
 277        struct buffer_head map_bh;
 278        sector_t start_blk, last_blk;
 279        loff_t isize = i_size_read(inode);
 280        u64 logical = 0, phys = 0, size = 0;
 281        u32 flags = FIEMAP_EXTENT_MERGED;
 282        bool past_eof = false, whole_file = false;
 283        int ret = 0;
 284
 285        ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 286        if (ret)
 287                return ret;
 288
 289        /*
 290         * Either the i_mutex or other appropriate locking needs to be held
 291         * since we expect isize to not change at all through the duration of
 292         * this call.
 293         */
 294        if (len >= isize) {
 295                whole_file = true;
 296                len = isize;
 297        }
 298
 299        /*
 300         * Some filesystems can't deal with being asked to map less than
 301         * blocksize, so make sure our len is at least block length.
 302         */
 303        if (logical_to_blk(inode, len) == 0)
 304                len = blk_to_logical(inode, 1);
 305
 306        start_blk = logical_to_blk(inode, start);
 307        last_blk = logical_to_blk(inode, start + len - 1);
 308
 309        do {
 310                /*
 311                 * we set b_size to the total size we want so it will map as
 312                 * many contiguous blocks as possible at once
 313                 */
 314                memset(&map_bh, 0, sizeof(struct buffer_head));
 315                map_bh.b_size = len;
 316
 317                ret = get_block(inode, start_blk, &map_bh, 0);
 318                if (ret)
 319                        break;
 320
 321                /* HOLE */
 322                if (!buffer_mapped(&map_bh)) {
 323                        start_blk++;
 324
 325                        /*
 326                         * We want to handle the case where there is an
 327                         * allocated block at the front of the file, and then
 328                         * nothing but holes up to the end of the file properly,
 329                         * to make sure that extent at the front gets properly
 330                         * marked with FIEMAP_EXTENT_LAST
 331                         */
 332                        if (!past_eof &&
 333                            blk_to_logical(inode, start_blk) >= isize)
 334                                past_eof = 1;
 335
 336                        /*
 337                         * First hole after going past the EOF, this is our
 338                         * last extent
 339                         */
 340                        if (past_eof && size) {
 341                                flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
 342                                ret = fiemap_fill_next_extent(fieinfo, logical,
 343                                                              phys, size,
 344                                                              flags);
 345                        } else if (size) {
 346                                ret = fiemap_fill_next_extent(fieinfo, logical,
 347                                                              phys, size, flags);
 348                                size = 0;
 349                        }
 350
 351                        /* if we have holes up to/past EOF then we're done */
 352                        if (start_blk > last_blk || past_eof || ret)
 353                                break;
 354                } else {
 355                        /*
 356                         * We have gone over the length of what we wanted to
 357                         * map, and it wasn't the entire file, so add the extent
 358                         * we got last time and exit.
 359                         *
 360                         * This is for the case where say we want to map all the
 361                         * way up to the second to the last block in a file, but
 362                         * the last block is a hole, making the second to last
 363                         * block FIEMAP_EXTENT_LAST.  In this case we want to
 364                         * see if there is a hole after the second to last block
 365                         * so we can mark it properly.  If we found data after
 366                         * we exceeded the length we were requesting, then we
 367                         * are good to go, just add the extent to the fieinfo
 368                         * and break
 369                         */
 370                        if (start_blk > last_blk && !whole_file) {
 371                                ret = fiemap_fill_next_extent(fieinfo, logical,
 372                                                              phys, size,
 373                                                              flags);
 374                                break;
 375                        }
 376
 377                        /*
 378                         * if size != 0 then we know we already have an extent
 379                         * to add, so add it.
 380                         */
 381                        if (size) {
 382                                ret = fiemap_fill_next_extent(fieinfo, logical,
 383                                                              phys, size,
 384                                                              flags);
 385                                if (ret)
 386                                        break;
 387                        }
 388
 389                        logical = blk_to_logical(inode, start_blk);
 390                        phys = blk_to_logical(inode, map_bh.b_blocknr);
 391                        size = map_bh.b_size;
 392                        flags = FIEMAP_EXTENT_MERGED;
 393
 394                        start_blk += logical_to_blk(inode, size);
 395
 396                        /*
 397                         * If we are past the EOF, then we need to make sure as
 398                         * soon as we find a hole that the last extent we found
 399                         * is marked with FIEMAP_EXTENT_LAST
 400                         */
 401                        if (!past_eof && logical + size >= isize)
 402                                past_eof = true;
 403                }
 404                cond_resched();
 405                if (fatal_signal_pending(current)) {
 406                        ret = -EINTR;
 407                        break;
 408                }
 409
 410        } while (1);
 411
 412        /* If ret is 1 then we just hit the end of the extent array */
 413        if (ret == 1)
 414                ret = 0;
 415
 416        return ret;
 417}
 418EXPORT_SYMBOL(__generic_block_fiemap);
 419
 420/**
 421 * generic_block_fiemap - FIEMAP for block based inodes
 422 * @inode: The inode to map
 423 * @fieinfo: The mapping information
 424 * @start: The initial block to map
 425 * @len: The length of the extect to attempt to map
 426 * @get_block: The block mapping function for the fs
 427 *
 428 * Calls __generic_block_fiemap to map the inode, after taking
 429 * the inode's mutex lock.
 430 */
 431
 432int generic_block_fiemap(struct inode *inode,
 433                         struct fiemap_extent_info *fieinfo, u64 start,
 434                         u64 len, get_block_t *get_block)
 435{
 436        int ret;
 437        inode_lock(inode);
 438        ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
 439        inode_unlock(inode);
 440        return ret;
 441}
 442EXPORT_SYMBOL(generic_block_fiemap);
 443
 444#endif  /*  CONFIG_BLOCK  */
 445
 446/*
 447 * This provides compatibility with legacy XFS pre-allocation ioctls
 448 * which predate the fallocate syscall.
 449 *
 450 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
 451 * are used here, rest are ignored.
 452 */
 453int ioctl_preallocate(struct file *filp, void __user *argp)
 454{
 455        struct inode *inode = file_inode(filp);
 456        struct space_resv sr;
 457
 458        if (copy_from_user(&sr, argp, sizeof(sr)))
 459                return -EFAULT;
 460
 461        switch (sr.l_whence) {
 462        case SEEK_SET:
 463                break;
 464        case SEEK_CUR:
 465                sr.l_start += filp->f_pos;
 466                break;
 467        case SEEK_END:
 468                sr.l_start += i_size_read(inode);
 469                break;
 470        default:
 471                return -EINVAL;
 472        }
 473
 474        return vfs_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
 475}
 476
 477static int file_ioctl(struct file *filp, unsigned int cmd,
 478                unsigned long arg)
 479{
 480        struct inode *inode = file_inode(filp);
 481        int __user *p = (int __user *)arg;
 482
 483        switch (cmd) {
 484        case FIBMAP:
 485                return ioctl_fibmap(filp, p);
 486        case FIONREAD:
 487                return put_user(i_size_read(inode) - filp->f_pos, p);
 488        case FS_IOC_RESVSP:
 489        case FS_IOC_RESVSP64:
 490                return ioctl_preallocate(filp, p);
 491        }
 492
 493        return vfs_ioctl(filp, cmd, arg);
 494}
 495
 496static int ioctl_fionbio(struct file *filp, int __user *argp)
 497{
 498        unsigned int flag;
 499        int on, error;
 500
 501        error = get_user(on, argp);
 502        if (error)
 503                return error;
 504        flag = O_NONBLOCK;
 505#ifdef __sparc__
 506        /* SunOS compatibility item. */
 507        if (O_NONBLOCK != O_NDELAY)
 508                flag |= O_NDELAY;
 509#endif
 510        spin_lock(&filp->f_lock);
 511        if (on)
 512                filp->f_flags |= flag;
 513        else
 514                filp->f_flags &= ~flag;
 515        spin_unlock(&filp->f_lock);
 516        return error;
 517}
 518
 519static int ioctl_fioasync(unsigned int fd, struct file *filp,
 520                          int __user *argp)
 521{
 522        unsigned int flag;
 523        int on, error;
 524
 525        error = get_user(on, argp);
 526        if (error)
 527                return error;
 528        flag = on ? FASYNC : 0;
 529
 530        /* Did FASYNC state change ? */
 531        if ((flag ^ filp->f_flags) & FASYNC) {
 532                if (filp->f_op->fasync)
 533                        /* fasync() adjusts filp->f_flags */
 534                        error = filp->f_op->fasync(fd, filp, on);
 535                else
 536                        error = -ENOTTY;
 537        }
 538        return error < 0 ? error : 0;
 539}
 540
 541static int ioctl_fsfreeze(struct file *filp)
 542{
 543        struct super_block *sb = file_inode(filp)->i_sb;
 544
 545        if (!capable(CAP_SYS_ADMIN))
 546                return -EPERM;
 547
 548        /* If filesystem doesn't support freeze feature, return. */
 549        if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
 550                return -EOPNOTSUPP;
 551
 552        /* Freeze */
 553        if (sb->s_op->freeze_super)
 554                return sb->s_op->freeze_super(sb);
 555        return freeze_super(sb);
 556}
 557
 558static int ioctl_fsthaw(struct file *filp)
 559{
 560        struct super_block *sb = file_inode(filp)->i_sb;
 561
 562        if (!capable(CAP_SYS_ADMIN))
 563                return -EPERM;
 564
 565        /* Thaw */
 566        if (sb->s_op->thaw_super)
 567                return sb->s_op->thaw_super(sb);
 568        return thaw_super(sb);
 569}
 570
 571static int ioctl_file_dedupe_range(struct file *file, void __user *arg)
 572{
 573        struct file_dedupe_range __user *argp = arg;
 574        struct file_dedupe_range *same = NULL;
 575        int ret;
 576        unsigned long size;
 577        u16 count;
 578
 579        if (get_user(count, &argp->dest_count)) {
 580                ret = -EFAULT;
 581                goto out;
 582        }
 583
 584        size = offsetof(struct file_dedupe_range __user, info[count]);
 585        if (size > PAGE_SIZE) {
 586                ret = -ENOMEM;
 587                goto out;
 588        }
 589
 590        same = memdup_user(argp, size);
 591        if (IS_ERR(same)) {
 592                ret = PTR_ERR(same);
 593                same = NULL;
 594                goto out;
 595        }
 596
 597        same->dest_count = count;
 598        ret = vfs_dedupe_file_range(file, same);
 599        if (ret)
 600                goto out;
 601
 602        ret = copy_to_user(argp, same, size);
 603        if (ret)
 604                ret = -EFAULT;
 605
 606out:
 607        kfree(same);
 608        return ret;
 609}
 610
 611/*
 612 * When you add any new common ioctls to the switches above and below
 613 * please update compat_sys_ioctl() too.
 614 *
 615 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
 616 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
 617 */
 618int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
 619             unsigned long arg)
 620{
 621        int error = 0;
 622        int __user *argp = (int __user *)arg;
 623        struct inode *inode = file_inode(filp);
 624
 625        switch (cmd) {
 626        case FIOCLEX:
 627                set_close_on_exec(fd, 1);
 628                break;
 629
 630        case FIONCLEX:
 631                set_close_on_exec(fd, 0);
 632                break;
 633
 634        case FIONBIO:
 635                error = ioctl_fionbio(filp, argp);
 636                break;
 637
 638        case FIOASYNC:
 639                error = ioctl_fioasync(fd, filp, argp);
 640                break;
 641
 642        case FIOQSIZE:
 643                if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
 644                    S_ISLNK(inode->i_mode)) {
 645                        loff_t res = inode_get_bytes(inode);
 646                        error = copy_to_user(argp, &res, sizeof(res)) ?
 647                                        -EFAULT : 0;
 648                } else
 649                        error = -ENOTTY;
 650                break;
 651
 652        case FIFREEZE:
 653                error = ioctl_fsfreeze(filp);
 654                break;
 655
 656        case FITHAW:
 657                error = ioctl_fsthaw(filp);
 658                break;
 659
 660        case FS_IOC_FIEMAP:
 661                return ioctl_fiemap(filp, arg);
 662
 663        case FIGETBSZ:
 664                return put_user(inode->i_sb->s_blocksize, argp);
 665
 666        case FICLONE:
 667                return ioctl_file_clone(filp, arg, 0, 0, 0);
 668
 669        case FICLONERANGE:
 670                return ioctl_file_clone_range(filp, argp);
 671
 672        case FIDEDUPERANGE:
 673                return ioctl_file_dedupe_range(filp, argp);
 674
 675        default:
 676                if (S_ISREG(inode->i_mode))
 677                        error = file_ioctl(filp, cmd, arg);
 678                else
 679                        error = vfs_ioctl(filp, cmd, arg);
 680                break;
 681        }
 682        return error;
 683}
 684
 685SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 686{
 687        int error;
 688        struct fd f = fdget(fd);
 689
 690        if (!f.file)
 691                return -EBADF;
 692        error = security_file_ioctl(f.file, cmd, arg);
 693        if (!error)
 694                error = do_vfs_ioctl(f.file, fd, cmd, arg);
 695        fdput(f);
 696        return error;
 697}
 698